Tobias Wulf
Labrary from Simon Blandford
Dependents: DiscoTech ADC_Test filter_implement IR_temperature ... more
Diff: adc.cpp
- Revision:
- 0:b05e4f5e2c8c
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/adc.cpp Mon Sep 23 11:18:37 2013 +0000
@@ -0,0 +1,439 @@
+/* mbed Library - ADC
+ * Copyright (c) 2010, sblandford
+ * released under MIT license http://mbed.org/licence/mit
+ */
+#include "mbed.h"
+#include "adc.h"
+
+
+ADC *ADC::instance;
+
+ADC::ADC(int sample_rate, int cclk_div)
+ {
+
+ int i, adc_clk_freq, pclk, clock_div, max_div=1;
+
+ //Work out CCLK
+ adc_clk_freq=CLKS_PER_SAMPLE*sample_rate;
+ int m = (LPC_SC->PLL0CFG & 0xFFFF) + 1;
+ int n = (LPC_SC->PLL0CFG >> 16) + 1;
+ int cclkdiv = LPC_SC->CCLKCFG + 1;
+ int Fcco = (2 * m * XTAL_FREQ) / n;
+ int cclk = Fcco / cclkdiv;
+
+ //Power up the ADC
+ LPC_SC->PCONP |= (1 << 12);
+ //Set clock at cclk / 1.
+ LPC_SC->PCLKSEL0 &= ~(0x3 << 24);
+ switch (cclk_div) {
+ case 1:
+ LPC_SC->PCLKSEL0 |= 0x1 << 24;
+ break;
+ case 2:
+ LPC_SC->PCLKSEL0 |= 0x2 << 24;
+ break;
+ case 4:
+ LPC_SC->PCLKSEL0 |= 0x0 << 24;
+ break;
+ case 8:
+ LPC_SC->PCLKSEL0 |= 0x3 << 24;
+ break;
+ default:
+ fprintf(stderr, "Warning: ADC CCLK clock divider must be 1, 2, 4 or 8. %u supplied.\n",
+ cclk_div);
+ fprintf(stderr, "Defaulting to 1.\n");
+ LPC_SC->PCLKSEL0 |= 0x1 << 24;
+ break;
+ }
+ pclk = cclk / cclk_div;
+ clock_div=pclk / adc_clk_freq;
+
+ if (clock_div > 0xFF) {
+ fprintf(stderr, "Warning: Clock division is %u which is above 255 limit. Re-Setting at limit.\n",
+ clock_div);
+ clock_div=0xFF;
+ }
+ if (clock_div == 0) {
+ fprintf(stderr, "Warning: Clock division is 0. Re-Setting to 1.\n");
+ clock_div=1;
+ }
+
+ _adc_clk_freq=pclk / clock_div;
+ if (_adc_clk_freq > MAX_ADC_CLOCK) {
+ fprintf(stderr, "Warning: Actual ADC sample rate of %u which is above %u limit\n",
+ _adc_clk_freq / CLKS_PER_SAMPLE, MAX_ADC_CLOCK / CLKS_PER_SAMPLE);
+ while ((pclk / max_div) > MAX_ADC_CLOCK) max_div++;
+ fprintf(stderr, "Maximum recommended sample rate is %u\n", (pclk / max_div) / CLKS_PER_SAMPLE);
+ }
+
+ LPC_ADC->ADCR =
+ ((clock_div - 1 ) << 8 ) | //Clkdiv
+ ( 1 << 21 ); //A/D operational
+
+ //Default no channels enabled
+ LPC_ADC->ADCR &= ~0xFF;
+ //Default NULL global custom isr
+ _adc_g_isr = NULL;
+ //Initialize arrays
+ for (i=7; i>=0; i--) {
+ _adc_data[i] = 0;
+ _adc_isr[i] = NULL;
+ }
+
+
+ //* Attach IRQ
+ instance = this;
+ NVIC_SetVector(ADC_IRQn, (uint32_t)&_adcisr);
+
+ //Disable global interrupt
+ LPC_ADC->ADINTEN &= ~0x100;
+
+};
+
+void ADC::_adcisr(void)
+{
+ instance->adcisr();
+}
+
+
+void ADC::adcisr(void)
+{
+ uint32_t stat;
+ int chan;
+
+ // Read status
+ stat = LPC_ADC->ADSTAT;
+ //Scan channels for over-run or done and update array
+ if (stat & 0x0101) _adc_data[0] = LPC_ADC->ADDR0;
+ if (stat & 0x0202) _adc_data[1] = LPC_ADC->ADDR1;
+ if (stat & 0x0404) _adc_data[2] = LPC_ADC->ADDR2;
+ if (stat & 0x0808) _adc_data[3] = LPC_ADC->ADDR3;
+ if (stat & 0x1010) _adc_data[4] = LPC_ADC->ADDR4;
+ if (stat & 0x2020) _adc_data[5] = LPC_ADC->ADDR5;
+ if (stat & 0x4040) _adc_data[6] = LPC_ADC->ADDR6;
+ if (stat & 0x8080) _adc_data[7] = LPC_ADC->ADDR7;
+
+ // Channel that triggered interrupt
+ chan = (LPC_ADC->ADGDR >> 24) & 0x07;
+ //User defined interrupt handlers
+ if (_adc_isr[chan] != NULL)
+ _adc_isr[chan](_adc_data[chan]);
+ if (_adc_g_isr != NULL)
+ _adc_g_isr(chan, _adc_data[chan]);
+ return;
+}
+
+int ADC::_pin_to_channel(PinName pin) {
+ int chan;
+ switch (pin) {
+ case p15://=p0.23 of LPC1768
+ default:
+ chan=0;
+ break;
+ case p16://=p0.24 of LPC1768
+ chan=1;
+ break;
+ case p17://=p0.25 of LPC1768
+ chan=2;
+ break;
+ case p18://=p0.26 of LPC1768
+ chan=3;
+ break;
+ case p19://=p1.30 of LPC1768
+ chan=4;
+ break;
+ case p20://=p1.31 of LPC1768
+ chan=5;
+ break;
+ }
+ return(chan);
+}
+
+PinName ADC::channel_to_pin(int chan) {
+ const PinName pin[8]={p15, p16, p17, p18, p19, p20, p15, p15};
+
+ if ((chan < 0) || (chan > 5))
+ fprintf(stderr, "ADC channel %u is outside range available to MBED pins.\n", chan);
+ return(pin[chan & 0x07]);
+}
+
+
+int ADC::channel_to_pin_number(int chan) {
+ const int pin[8]={15, 16, 17, 18, 19, 20, 0, 0};
+
+ if ((chan < 0) || (chan > 5))
+ fprintf(stderr, "ADC channel %u is outside range available to MBED pins.\n", chan);
+ return(pin[chan & 0x07]);
+}
+
+
+uint32_t ADC::_data_of_pin(PinName pin) {
+ //If in burst mode and at least one interrupt enabled then
+ //take all values from _adc_data
+ if (burst() && (LPC_ADC->ADINTEN & 0x3F)) {
+ return(_adc_data[_pin_to_channel(pin)]);
+ } else {
+ //Return current register value or last value from interrupt
+ switch (pin) {
+ case p15://=p0.23 of LPC1768
+ default:
+ return(LPC_ADC->ADINTEN & 0x01?_adc_data[0]:LPC_ADC->ADDR0);
+ case p16://=p0.24 of LPC1768
+ return(LPC_ADC->ADINTEN & 0x02?_adc_data[1]:LPC_ADC->ADDR1);
+ case p17://=p0.25 of LPC1768
+ return(LPC_ADC->ADINTEN & 0x04?_adc_data[2]:LPC_ADC->ADDR2);
+ case p18://=p0.26 of LPC1768:
+ return(LPC_ADC->ADINTEN & 0x08?_adc_data[3]:LPC_ADC->ADDR3);
+ case p19://=p1.30 of LPC1768
+ return(LPC_ADC->ADINTEN & 0x10?_adc_data[4]:LPC_ADC->ADDR4);
+ case p20://=p1.31 of LPC1768
+ return(LPC_ADC->ADINTEN & 0x20?_adc_data[5]:LPC_ADC->ADDR5);
+ }
+ }
+}
+
+//Enable or disable an ADC pin
+void ADC::setup(PinName pin, int state) {
+ int chan;
+ chan=_pin_to_channel(pin);
+ if ((state & 1) == 1) {
+ switch(pin) {
+ case p15://=p0.23 of LPC1768
+ default:
+ LPC_PINCON->PINSEL1 &= ~((unsigned int)0x3 << 14);
+ LPC_PINCON->PINSEL1 |= (unsigned int)0x1 << 14;
+ LPC_PINCON->PINMODE1 &= ~((unsigned int)0x3 << 14);
+ LPC_PINCON->PINMODE1 |= (unsigned int)0x2 << 14;
+ break;
+ case p16://=p0.24 of LPC1768
+ LPC_PINCON->PINSEL1 &= ~((unsigned int)0x3 << 16);
+ LPC_PINCON->PINSEL1 |= (unsigned int)0x1 << 16;
+ LPC_PINCON->PINMODE1 &= ~((unsigned int)0x3 << 16);
+ LPC_PINCON->PINMODE1 |= (unsigned int)0x2 << 16;
+ break;
+ case p17://=p0.25 of LPC1768
+ LPC_PINCON->PINSEL1 &= ~((unsigned int)0x3 << 18);
+ LPC_PINCON->PINSEL1 |= (unsigned int)0x1 << 18;
+ LPC_PINCON->PINMODE1 &= ~((unsigned int)0x3 << 18);
+ LPC_PINCON->PINMODE1 |= (unsigned int)0x2 << 18;
+ break;
+ case p18://=p0.26 of LPC1768:
+ LPC_PINCON->PINSEL1 &= ~((unsigned int)0x3 << 20);
+ LPC_PINCON->PINSEL1 |= (unsigned int)0x1 << 20;
+ LPC_PINCON->PINMODE1 &= ~((unsigned int)0x3 << 20);
+ LPC_PINCON->PINMODE1 |= (unsigned int)0x2 << 20;
+ break;
+ case p19://=p1.30 of LPC1768
+ LPC_PINCON->PINSEL3 &= ~((unsigned int)0x3 << 28);
+ LPC_PINCON->PINSEL3 |= (unsigned int)0x3 << 28;
+ LPC_PINCON->PINMODE3 &= ~((unsigned int)0x3 << 28);
+ LPC_PINCON->PINMODE3 |= (unsigned int)0x2 << 28;
+ break;
+ case p20://=p1.31 of LPC1768
+ LPC_PINCON->PINSEL3 &= ~((unsigned int)0x3 << 30);
+ LPC_PINCON->PINSEL3 |= (unsigned int)0x3 << 30;
+ LPC_PINCON->PINMODE3 &= ~((unsigned int)0x3 << 30);
+ LPC_PINCON->PINMODE3 |= (unsigned int)0x2 << 30;
+ break;
+ }
+ //Only one channel can be selected at a time if not in burst mode
+ if (!burst()) LPC_ADC->ADCR &= ~0xFF;
+ //Select channel
+ LPC_ADC->ADCR |= (1 << chan);
+ }
+ else {
+ switch(pin) {
+ case p15://=p0.23 of LPC1768
+ default:
+ LPC_PINCON->PINSEL1 &= ~((unsigned int)0x3 << 14);
+ LPC_PINCON->PINMODE1 &= ~((unsigned int)0x3 << 14);
+ break;
+ case p16://=p0.24 of LPC1768
+ LPC_PINCON->PINSEL1 &= ~((unsigned int)0x3 << 16);
+ LPC_PINCON->PINMODE1 &= ~((unsigned int)0x3 << 16);
+ break;
+ case p17://=p0.25 of LPC1768
+ LPC_PINCON->PINSEL1 &= ~((unsigned int)0x3 << 18);
+ LPC_PINCON->PINMODE1 &= ~((unsigned int)0x3 << 18);
+ break;
+ case p18://=p0.26 of LPC1768:
+ LPC_PINCON->PINSEL1 &= ~((unsigned int)0x3 << 20);
+ LPC_PINCON->PINMODE1 &= ~((unsigned int)0x3 << 20);
+ break;
+ case p19://=p1.30 of LPC1768
+ LPC_PINCON->PINSEL3 &= ~((unsigned int)0x3 << 28);
+ LPC_PINCON->PINMODE3 &= ~((unsigned int)0x3 << 28);
+ break;
+ case p20://=p1.31 of LPC1768
+ LPC_PINCON->PINSEL3 &= ~((unsigned int)0x3 << 30);
+ LPC_PINCON->PINMODE3 &= ~((unsigned int)0x3 << 30);
+ break;
+ }
+ LPC_ADC->ADCR &= ~(1 << chan);
+ }
+}
+//Return channel enabled/disabled state
+int ADC::setup(PinName pin) {
+ int chan;
+
+ chan = _pin_to_channel(pin);
+ return((LPC_ADC->ADCR & (1 << chan)) >> chan);
+}
+
+//Select channel already setup
+void ADC::select(PinName pin) {
+ int chan;
+
+ //Only one channel can be selected at a time if not in burst mode
+ if (!burst()) LPC_ADC->ADCR &= ~0xFF;
+ //Select channel
+ chan = _pin_to_channel(pin);
+ LPC_ADC->ADCR |= (1 << chan);
+}
+
+//Enable or disable burst mode
+void ADC::burst(int state) {
+ if ((state & 1) == 1) {
+ if (startmode(0) != 0)
+ fprintf(stderr, "Warning. startmode is %u. Must be 0 for burst mode.\n", startmode(0));
+ LPC_ADC->ADCR |= (1 << 16);
+ }
+ else
+ LPC_ADC->ADCR &= ~(1 << 16);
+}
+//Return burst mode state
+int ADC::burst(void) {
+ return((LPC_ADC->ADCR & (1 << 16)) >> 16);
+}
+
+//Set startmode and edge
+void ADC::startmode(int mode, int edge) {
+ int lpc_adc_temp;
+
+ //Reset start mode and edge bit,
+ lpc_adc_temp = LPC_ADC->ADCR & ~(0x0F << 24);
+ //Write with new values
+ lpc_adc_temp |= ((mode & 7) << 24) | ((edge & 1) << 27);
+ LPC_ADC->ADCR = lpc_adc_temp;
+}
+
+//Return startmode state according to mode_edge=0: mode and mode_edge=1: edge
+int ADC::startmode(int mode_edge){
+ switch (mode_edge) {
+ case 0:
+ default:
+ return((LPC_ADC->ADCR >> 24) & 0x07);
+ case 1:
+ return((LPC_ADC->ADCR >> 27) & 0x01);
+ }
+}
+
+//Start ADC conversion
+void ADC::start(void) {
+ startmode(1,0);
+}
+
+
+//Set interrupt enable/disable for pin to state
+void ADC::interrupt_state(PinName pin, int state) {
+ int chan;
+
+ chan = _pin_to_channel(pin);
+ if (state == 1) {
+ LPC_ADC->ADINTEN &= ~0x100;
+ LPC_ADC->ADINTEN |= 1 << chan;
+ /* Enable the ADC Interrupt */
+ NVIC_EnableIRQ(ADC_IRQn);
+ } else {
+ LPC_ADC->ADINTEN &= ~( 1 << chan );
+ //Disable interrrupt if no active pins left
+ if ((LPC_ADC->ADINTEN & 0xFF) == 0)
+ NVIC_DisableIRQ(ADC_IRQn);
+ }
+}
+
+//Return enable/disable state of interrupt for pin
+int ADC::interrupt_state(PinName pin) {
+ int chan;
+
+ chan = _pin_to_channel(pin);
+ return((LPC_ADC->ADINTEN >> chan) & 0x01);
+}
+
+
+//Attach custom interrupt handler replacing default
+void ADC::attach(void(*fptr)(void)) {
+ //* Attach IRQ
+ NVIC_SetVector(ADC_IRQn, (uint32_t)fptr);
+}
+
+//Restore default interrupt handler
+void ADC::detach(void) {
+ //* Attach IRQ
+ instance = this;
+ NVIC_SetVector(ADC_IRQn, (uint32_t)&_adcisr);
+}
+
+
+//Append interrupt handler for pin to function isr
+void ADC::append(PinName pin, void(*fptr)(uint32_t value)) {
+ int chan;
+
+ chan = _pin_to_channel(pin);
+ _adc_isr[chan] = fptr;
+}
+
+//Append interrupt handler for pin to function isr
+void ADC::unappend(PinName pin) {
+ int chan;
+
+ chan = _pin_to_channel(pin);
+ _adc_isr[chan] = NULL;
+}
+
+//Unappend global interrupt handler to function isr
+void ADC::append(void(*fptr)(int chan, uint32_t value)) {
+ _adc_g_isr = fptr;
+}
+
+//Detach global interrupt handler to function isr
+void ADC::unappend() {
+ _adc_g_isr = NULL;
+}
+
+//Set ADC offset
+void offset(int offset) {
+ LPC_ADC->ADTRM &= ~(0x07 << 4);
+ LPC_ADC->ADTRM |= (offset & 0x07) << 4;
+}
+
+//Return current ADC offset
+int offset(void) {
+ return((LPC_ADC->ADTRM >> 4) & 0x07);
+}
+
+//Return value of ADC on pin
+int ADC::read(PinName pin) {
+ //Reset DONE and OVERRUN flags of interrupt handled ADC data
+ _adc_data[_pin_to_channel(pin)] &= ~(((uint32_t)0x01 << 31) | ((uint32_t)0x01 << 30));
+ //Return value
+ return((_data_of_pin(pin) >> 4) & 0xFFF);
+}
+
+//Return DONE flag of ADC on pin
+int ADC::done(PinName pin) {
+ return((_data_of_pin(pin) >> 31) & 0x01);
+}
+
+//Return OVERRUN flag of ADC on pin
+int ADC::overrun(PinName pin) {
+ return((_data_of_pin(pin) >> 30) & 0x01);
+}
+
+int ADC::actual_adc_clock(void) {
+ return(_adc_clk_freq);
+}
+
+int ADC::actual_sample_rate(void) {
+ return(_adc_clk_freq / CLKS_PER_SAMPLE);
+}